In a small bowl, sprinkle the gelatin over two tablespoons lemon juice. Set aside to soften. In a medium stainless steel bowl, or top of a double boiler, combine the remaining ingredients. Set the bowl over, but not in, simmering water. (Although it may be cooked directly on a low flame in a heavy saucepan, using a bain marie or water bath insures that it won't overcook.)

Whisk constantly until the curd is thick and coats the back of a soup spoon, about five minutes. Stir in the gelatin mixture and cook one minute longer. Strain into a medium bowl and allow to cool to room temperature, whisking occasionally.

Transfer to a clean, dry jar, cover and refrigerate until ready to use. The curd will keep about one week.